1/* 2 * Copyright (C) 2001 Lennert Buytenhek (buytenh@gnu.org) 3 * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) 4 * Licensed under the GPL 5 */ 6 7#include <errno.h> 8#include <string.h> 9#include <unistd.h> 10#include <sys/socket.h> 11#include <sys/uio.h> 12#include <sys/un.h> 13#include "kern_constants.h" 14#include "mconsole.h" 15#include "user.h" 16 17static struct mconsole_command commands[] = { 18 /* 19 * With uts namespaces, uts information becomes process-specific, so 20 * we need a process context. If we try handling this in interrupt 21 * context, we may hit an exiting process without a valid uts 22 * namespace. 23 */ 24 { "version", mconsole_version, MCONSOLE_PROC }, 25 { "halt", mconsole_halt, MCONSOLE_PROC }, 26 { "reboot", mconsole_reboot, MCONSOLE_PROC }, 27 { "config", mconsole_config, MCONSOLE_PROC }, 28 { "remove", mconsole_remove, MCONSOLE_PROC }, 29 { "sysrq", mconsole_sysrq, MCONSOLE_INTR }, 30 { "help", mconsole_help, MCONSOLE_INTR }, 31 { "cad", mconsole_cad, MCONSOLE_INTR }, 32 { "stop", mconsole_stop, MCONSOLE_PROC }, 33 { "go", mconsole_go, MCONSOLE_INTR }, 34 { "log", mconsole_log, MCONSOLE_INTR }, 35 { "proc", mconsole_proc, MCONSOLE_PROC }, 36 { "stack", mconsole_stack, MCONSOLE_INTR }, 37}; 38 39/* Initialized in mconsole_init, which is an initcall */ 40char mconsole_socket_name[256]; 41 42static int mconsole_reply_v0(struct mc_request *req, char *reply) 43{ 44 struct iovec iov; 45 struct msghdr msg; 46 47 iov.iov_base = reply; 48 iov.iov_len = strlen(reply); 49 50 msg.msg_name = &(req->origin); 51 msg.msg_namelen = req->originlen; 52 msg.msg_iov = &iov; 53 msg.msg_iovlen = 1; 54 msg.msg_control = NULL; 55 msg.msg_controllen = 0; 56 msg.msg_flags = 0; 57 58 return sendmsg(req->originating_fd, &msg, 0); 59} 60 61static struct mconsole_command *mconsole_parse(struct mc_request *req) 62{ 63 struct mconsole_command *cmd; 64 int i; 65 66 for (i = 0; i < ARRAY_SIZE(commands); i++) { 67 cmd = &commands[i]; 68 if (!strncmp(req->request.data, cmd->command, 69 strlen(cmd->command))) { 70 return cmd; 71 } 72 } 73 return NULL; 74} 75 76#define MIN(a,b) ((a)<(b) ? (a):(b)) 77 78#define STRINGX(x) #x 79#define STRING(x) STRINGX(x) 80 81int mconsole_get_request(int fd, struct mc_request *req) 82{ 83 int len; 84 85 req->originlen = sizeof(req->origin); 86 req->len = recvfrom(fd, &req->request, sizeof(req->request), 0, 87 (struct sockaddr *) req->origin, &req->originlen); 88 if (req->len < 0) 89 return 0; 90 91 req->originating_fd = fd; 92 93 if (req->request.magic != MCONSOLE_MAGIC) { 94 /* Unversioned request */ 95 len = MIN(sizeof(req->request.data) - 1, 96 strlen((char *) &req->request)); 97 memmove(req->request.data, &req->request, len); 98 req->request.data[len] = '\0'; 99 100 req->request.magic = MCONSOLE_MAGIC; 101 req->request.version = 0; 102 req->request.len = len; 103 104 mconsole_reply_v0(req, "ERR Version 0 mconsole clients are " 105 "not supported by this driver"); 106 return 0; 107 } 108 109 if (req->request.len >= MCONSOLE_MAX_DATA) { 110 mconsole_reply(req, "Request too large", 1, 0); 111 return 0; 112 } 113 if (req->request.version != MCONSOLE_VERSION) { 114 mconsole_reply(req, "This driver only supports version " 115 STRING(MCONSOLE_VERSION) " clients", 1, 0); 116 } 117 118 req->request.data[req->request.len] = '\0'; 119 req->cmd = mconsole_parse(req); 120 if (req->cmd == NULL) { 121 mconsole_reply(req, "Unknown command", 1, 0); 122 return 0; 123 } 124 125 return 1; 126} 127 128int mconsole_reply_len(struct mc_request *req, const char *str, int total, 129 int err, int more) 130{ 131 struct mconsole_reply reply; 132 int len, n; 133 134 do { 135 reply.err = err; 136 137 /* err can only be true on the first packet */ 138 err = 0; 139 140 len = MIN(total, MCONSOLE_MAX_DATA - 1); 141 142 if (len == total) reply.more = more; 143 else reply.more = 1; 144 145 memcpy(reply.data, str, len); 146 reply.data[len] = '\0'; 147 total -= len; 148 str += len; 149 reply.len = len + 1; 150 151 len = sizeof(reply) + reply.len - sizeof(reply.data); 152 153 n = sendto(req->originating_fd, &reply, len, 0, 154 (struct sockaddr *) req->origin, req->originlen); 155 156 if (n < 0) 157 return -errno; 158 } while (total > 0); 159 return 0; 160} 161 162int mconsole_reply(struct mc_request *req, const char *str, int err, int more) 163{ 164 return mconsole_reply_len(req, str, strlen(str), err, more); 165} 166 167 168int mconsole_unlink_socket(void) 169{ 170 unlink(mconsole_socket_name); 171 return 0; 172} 173 174static int notify_sock = -1; 175 176int mconsole_notify(char *sock_name, int type, const void *data, int len) 177{ 178 struct sockaddr_un target; 179 struct mconsole_notify packet; 180 int n, err = 0; 181 182 lock_notify(); 183 if (notify_sock < 0) { 184 notify_sock = socket(PF_UNIX, SOCK_DGRAM, 0); 185 if (notify_sock < 0) { 186 err = -errno; 187 printk(UM_KERN_ERR "mconsole_notify - socket failed, " 188 "errno = %d\n", errno); 189 } 190 } 191 unlock_notify(); 192 193 if (err) 194 return err; 195 196 target.sun_family = AF_UNIX; 197 strcpy(target.sun_path, sock_name); 198 199 packet.magic = MCONSOLE_MAGIC; 200 packet.version = MCONSOLE_VERSION; 201 packet.type = type; 202 len = (len > sizeof(packet.data)) ? sizeof(packet.data) : len; 203 packet.len = len; 204 memcpy(packet.data, data, len); 205 206 err = 0; 207 len = sizeof(packet) + packet.len - sizeof(packet.data); 208 n = sendto(notify_sock, &packet, len, 0, (struct sockaddr *) &target, 209 sizeof(target)); 210 if (n < 0) { 211 err = -errno; 212 printk(UM_KERN_ERR "mconsole_notify - sendto failed, " 213 "errno = %d\n", errno); 214 } 215 return err; 216} 217